Dark Sky Dreams Dashed By The Overly Bright Side Of LED Lighting - CleanTechnica

Oct 15, 2024

A recent story in the Milwaukee Journal Sentinel tells the sad story of a dark sky park that almost was. But dreams of establishing a new refuge away from the lights of the city were dashed by an unlikely culprit: efficient LED lighting technology. In this article, I want to briefly share the story, explain why it matters, and then what we can do to improve the situation.

The Journal Sentinel article starts out telling us about an astronomy educator who was spearheading an effort to establish three new international dark sky parks at Wildcat Mountain State Park, Kickapoo Valley Reserve, and Tunnelville Cliffs. The designation not only means a place is good and dark at night, but it also attracts tourism from people looking to get a great view of the stars, as well as efforts to keep the areas dark.

After taking some measurements of light levels in the three areas, John Heasley found that the light levels for all of these parks made them eligible for international dark sky park status. So, the work on getting them into the registry began in earnest in 2021.

Sadly, these dreams were dashed in 2023 when foll0w-up measurements were taken. In some of the areas, the parks’ brightness levels had increased by more than 50%! This put them out of the eligibility criteria. “It was a blow. It was a disappointment,” Heasley told the Journal Sentinel. “We had done so much work to create this international dark sky park.”

The problem is simple: widespread misuse of LED lights.

Overall, LED lights are a good thing. They use far less energy. They don’t need to be replaced nearly as often as incandescent bulbs. They don’t have the toxic chemicals that compact fluorescent (aka “twisty”) bulbs, making them a lot more friendly for safe disposal. The more white or bluish color temperature makes it easier for people to feel like they’re seeing at night.

But there’s a dark side. Or, put more accurately, an overly bright side. Because LED lights are cheaper to operate, people and businesses are a lot less afraid to run more of them at night and buy brighter bulbs. Cities themselves (the governments) are also putting in brighter and brighter lights along roadways, at city parks, and at sporting facilities. This has led cities to become a lot brighter even while using less energy.

This might feel good to people living in the cities who enjoy the brighter light at night, but the light doesn’t stay where it’s made. Not only does the light go directly out from the last houses on the outskirts of the city, but cities as a whole cast a lot of light into the sky that reflects back down for dozens of miles, if not more.

This is what these hoped-for dark sky parks fell victim to.

I know many people don’t see the value of a dark night, and honestly, I get it. If people in cities and small towns are safer and more comfortable, why should we be more worried about tourist-oriented things like parks?

The truth might surprise you, though.

First off, the benefits of light at night aren’t unlimited. There does come a point where additional light leads to not only diminishing returns, but even a decline in safety. Excess light can blind drivers, create shadows that criminals can hide in, and ruin sleep quality. In many places, we’ve passed that point and gone right back into the danger zone where sleepy drivers can’t see and robbers can more easily ambush innocent people.

Messing up sleep cycles can be bad for both humans and other animals. For all living things, too much light at night messes up not only our sleep (which is essential to good health), but also throws the balance of hormones in our bodies out of whack. Links between excess light at night and heart disease, obesity, and cancer have all been found. This is obviously bad.

Non-human animals have it even worse. We can put up blackout curtains and otherwise make it possible to sleep, but when you live outside, the life-and-death problems from lighting up the night can come at you a lot faster. It’s harder to hide at night if you’re prey. It’s harder to hunt if you’re a predator. Navigation of everything from bugs to birds gets messed up, as lights can be confused for the moon or the stars. So, instead of possibly dying from cancer or heart disease later, animals are out there dying tonight.

Even though all of the above is obviously worse, the value of having dark places to escape to shouldn’t be ignored. Being able to go out and see the Milky Way the way our ancestors did can be good for our mental health and help us feel more connected to nature. What good are we without our mental health and emotional well-being?

I don’t want to be all about doom and gloom here. This isn’t an unsolvable problem that will haunt the planet for generations to come. It’s literally something we could solve immediately if enough of the public became both aware of the problem and willing to do something about it.

Being willing to do something about it is a lot easier when you consider that you don’t need to sacrifice needed light. The problem can be solved while still giving you the light you need for safety and even fun.

There are several types of wasted light that we can get rid of without losing out on anything. Light that’s overly bright, light that’s going places where we don’t need it, and light that’s the wrong color all add up to ruining the dark sky at night. Eliminate those, while keeping light where it’s needed and in the desired amount, and we’re good.

For bulbs, the choice is simple, somewhat dimmer bulbs that project a more yellowish hue. Just a minor reduction in brightness and a slight shift to the yellow means a lot less interference.

Keeping light where it’s needed is as easy as buying the right light fixture. Instead of sending light in all directions, pointing the light down to where we need it is the key. This not only keeps the extra light out of the sky, but out of your neighbors’ windows and away from people driving or walking by. Even better: add a timer or motion sensor to make the light only come on when you want it.

If everyone did just these few things, we’d be in great shape!

Featured image and other image by Jennifer Sensiba.

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